Advances in polymerization processes and catalysts have produced new polymers having improved physical and mechanical properties useful in a wide variety of products and applications. With the development of new catalysts, the choice of polymerization, such as solution, slurry, high pressure or gas phase, for producing a particular polymer has been greatly expanded. Advances in polymerization technology have also provided more efficient, highly productive and economically enhanced processes.
A number of different techniques have been developed for delivering reactor components, such as continuity additives and catalysts, to polymerization reactors. One technique involves delivery of the reactor components to the reactor in a mineral oil slurry with the reactor component suspended in a mineral oil. While these mineral oil slurries have been used successfully for reactor component delivery, their use can be challenging because the reactor components often settle from the slurries prior to use. Accordingly, the reactor component storage containers need to be agitated to re-suspend the reactor component in the mineral oil. For example, certain reactor components, such as polyethyleneimine, may require continuous, vigorous agitation to keep the hydrophilic polyethyleneimine suspended in the mineral oil. In addition, special precautions may need to be taken to avoid settling of the reactor component in the lines which feed the reactor. For example, smaller diameter lines could be used to help maintain high velocity of the mineral oil slurry, but this can lead to high pressure drops or line plugging. Alternately, lines may need to be steeply sloped to the reactor, which can then complicate the layout in typical chemical plants. Moreover, because certain catalyst components, such as solid metallocene catalysts, settle too quickly in the mineral oil liquid, solutions of the catalyst component have been used in place of the mineral oil slurries. However, the use of the solutions poses challenges in the compatibility of certain solvents, such as toluene, with the polymerization process.
Accordingly, there exists a need for improved polymerization processes, for example, improved techniques for delivering reactor components to a polymerization reactor. Such techniques may reduce the tendency of the reactor components to settle before they reach the polymerization reactor.